George Michael has lost 15lbs since giving up marijuana.
The 47-year-old singer insists he has been clean since completing four weeks of an eight-week prison term for driving under the influence of drugs last September and has been delighted by some of the unexpected side effects of quitting his cannabis high, which is known for triggering a sudden desire for food in users.
He said: "I'm having therapy about my ongoing drug abuse.
"Hopefully the period where I was a bit lost is over for good. I hope it's self evident just in the fact I've lost about 15lbs, I hope it's self-evident I'm not eating as much any more, which should tell you a lot. "None of my trousers fit anymore, for the right reasons this time.
"I've dropped about 14 or 15lbs without really trying."
Despite his weight loss, George is not convinced he will stay slender and hasn't yet accepted his slim frame enough to shop for new clothes.
He added in an interview with UK station BBC Radio 2: "I've always been the porky boy in my head. I didn't know on the last tour I was carrying all that extra weight! Now if anything, I'm a little bit skinny.
"I have two pairs of black jeans and they're the only ones that fit me. In my head I obviously think I'm going to put the weight back on so I haven't bought any new jeans.
As well as losing weight, George says his sobriety has given him more "courage" to try new things and tackle parts of his life he had previously kept hidden.
He said: "I struggle to have more hours of social time because I'm trying to be a very good boy, that's a struggle but the work part is easy.
"I went through a long period where I was afraid of doing things I wanted to do, and you get your courage back, which is what's important. Some days it's fearlessness, but I wouldn't normally go that far. There are aspects of my life that I treasure which I couldn't get my hands on in a weird way over the last 15 years and I can now, it's a bizarre feeling."